Mix the vinegar and mustard; season to taste with salt and pepper. Slowly whisk in oils; reserve. To assemble salad, cut each avocado half into 3 slices; fan around the outside perimeter of the plate. Place the orange segments between the avocado slices; sprinkle both with salt and pepper. Toss the frisee with 1/2 tablespoon of vinaigrette; place in the center of the plate. Garnish with roma tomato and toasted pecans;drizzle with remaining vinaigrette.